This patch series introduces UFFDIO_MOVE feature to userfaultfd, which
has long been implemented and maintained by Andrea in his local tree [1],
but was not upstreamed due to lack of use cases where this approach would
be better than allocating a new page and copying the contents. Previous
upstraming attempts could be found at [6] and [7].
UFFDIO_COPY performs ~20% better than UFFDIO_MOVE when the application
needs pages to be allocated [2]. However, with UFFDIO_MOVE, if pages are
available (in userspace) for recycling, as is usually the case in heap
compaction algorithms, then we can avoid the page allocation and memcpy
(done by UFFDIO_COPY). Also, since the pages are recycled in the
userspace, we avoid the need to release (via madvise) the pages back to
the kernel [3].
We see over 40% reduction (on a Google pixel 6 device) in the compacting
thread’s completion time by using UFFDIO_MOVE vs. UFFDIO_COPY. This was
measured using a benchmark that emulates a heap compaction implementation
using userfaultfd (to allow concurrent accesses by application threads).
More details of the usecase are explained in [3].
Furthermore, UFFDIO_MOVE enables moving swapped-out pages without
touching them within the same vma. Today, it can only be done by mremap,
however it forces splitting the vma.
TODOs for follow-up improvements:
- cross-mm support. Known differences from single-mm and missing pieces:
- memcg recharging (might need to isolate pages in the process)
- mm counters
- cross-mm deposit table moves
- cross-mm test
- document the address space where src and dest reside in struct
uffdio_move
- TLB flush batching. Will require extensive changes to PTL locking in
move_pages_pte(). OTOH that might let us reuse parts of mremap code.
Changes since v4 [9]:
- added Acked-by in patch 1, per Peter Xu
- added description for ctx, mm and mode parameters of move_pages(),
per kernel test robot
- added Reviewed-by's, per Peter Xu and Axel Rasmussen
- removed unused operations in uffd_test_case_ops
- refactored uffd-unit-test changes to avoid using global variables and
handle pmd moves without page size overrides, per Peter Xu
Changes since v3 [8]:
- changed retry path in folio_lock_anon_vma_read() to unlock and then
relock RCU, per Peter Xu
- removed cross-mm support from initial patchset, per David Hildenbrand
- replaced BUG_ONs with VM_WARN_ON or WARN_ON_ONCE, per David Hildenbrand
- added missing cache flushing, per Lokesh Gidra and Peter Xu
- updated manpage text in the patch description, per Peter Xu
- renamed internal functions from "remap" to "move", per Peter Xu
- added mmap_changing check after taking mmap_lock, per Peter Xu
- changed uffd context check to ensure dst_mm is registered onto uffd we
are operating on, Peter Xu and David Hildenbrand
- changed to non-maybe variants of maybe*_mkwrite(), per David Hildenbrand
- fixed warning for CONFIG_TRANSPARENT_HUGEPAGE=n, per kernel test robot
- comments cleanup, per David Hildenbrand and Peter Xu
- checks for VM_IO,VM_PFNMAP,VM_HUGETLB,..., per David Hildenbrand
- prevent moving pinned pages, per Peter Xu
- changed uffd tests to call move uffd_test_ctx_clear() at the end of the
test run instead of in the beginning of the next run
- added support for testcase-specific ops
- added test for moving PMD-aligned blocks
Changes since v2 [5]:
- renamed UFFDIO_REMAP to UFFDIO_MOVE, per David Hildenbrand
- rebase over mm-unstable to use folio_move_anon_rmap(),
per David Hildenbrand
- added text for manpage explaining DONTFORK and KSM requirements for this
feature, per David Hildenbrand
- check for anon_vma changes in the fast path of folio_lock_anon_vma_read,
per Peter Xu
- updated the title and description of the first patch,
per David Hildenbrand
- updating comments in folio_lock_anon_vma_read() explaining the need for
anon_vma checks, per David Hildenbrand
- changed all mapcount checks to PageAnonExclusive, per Jann Horn and
David Hildenbrand
- changed counters in remap_swap_pte() from MM_ANONPAGES to MM_SWAPENTS,
per Jann Horn
- added a check for PTE change after folio is locked in remap_pages_pte(),
per Jann Horn
- added handling of PMD migration entries and bailout when pmd_devmap(),
per Jann Horn
- added checks to ensure both src and dst VMAs are writable, per Peter Xu
- added UFFD_FEATURE_MOVE, per Peter Xu
- removed obsolete comments, per Peter Xu
- renamed remap_anon_pte to remap_present_pte, per Peter Xu
- added a comment for folio_get_anon_vma() explaining the need for
anon_vma checks, per Peter Xu
- changed error handling in remap_pages() to make it more clear,
per Peter Xu
- changed EFAULT to EAGAIN to retry when a hugepage appears or disappears
from under us, per Peter Xu
- added links to previous upstreaming attempts, per David Hildenbrand
Changes since v1 [4]:
- add mmget_not_zero in userfaultfd_remap, per Jann Horn
- removed extern from function definitions, per Matthew Wilcox
- converted to folios in remap_pages_huge_pmd, per Matthew Wilcox
- use PageAnonExclusive in remap_pages_huge_pmd, per David Hildenbrand
- handle pgtable transfers between MMs, per Jann Horn
- ignore concurrent A/D pte bit changes, per Jann Horn
- split functions into smaller units, per David Hildenbrand
- test for folio_test_large in remap_anon_pte, per Matthew Wilcox
- use pte_swp_exclusive for swapcount check, per David Hildenbrand
- eliminated use of mmu_notifier_invalidate_range_start_nonblock,
per Jann Horn
- simplified THP alignment checks, per Jann Horn
- refactored the loop inside remap_pages, per Jann Horn
- additional clarifying comments, per Jann Horn
Main changes since Andrea's last version [1]:
- Trivial translations from page to folio, mmap_sem to mmap_lock
- Replace pmd_trans_unstable() with pte_offset_map_nolock() and handle its
possible failure
- Move pte mapping into remap_pages_pte to allow for retries when source
page or anon_vma is contended. Since pte_offset_map_nolock() start RCU
read section, we can't block anymore after mapping a pte, so have to unmap
the ptesm do the locking and retry.
- Add and use anon_vma_trylock_write() to avoid blocking while in RCU
read section.
- Accommodate changes in mmu_notifier_range_init() API, switch to
mmu_notifier_invalidate_range_start_nonblock() to avoid blocking while in
RCU read section.
- Open-code now removed __swp_swapcount()
- Replace pmd_read_atomic() with pmdp_get_lockless()
- Add new selftest for UFFDIO_MOVE
[1] https://gitlab.com/aarcange/aa/-/commit/2aec7aea56b10438a3881a20a411aa4b1fc…
[2] https://lore.kernel.org/all/1425575884-2574-1-git-send-email-aarcange@redha…
[3] https://lore.kernel.org/linux-mm/CA+EESO4uO84SSnBhArH4HvLNhaUQ5nZKNKXqxRCyj…
[4] https://lore.kernel.org/all/20230914152620.2743033-1-surenb@google.com/
[5] https://lore.kernel.org/all/20230923013148.1390521-1-surenb@google.com/
[6] https://lore.kernel.org/all/1425575884-2574-21-git-send-email-aarcange@redh…
[7] https://lore.kernel.org/all/cover.1547251023.git.blake.caldwell@colorado.ed…
[8] https://lore.kernel.org/all/20231009064230.2952396-1-surenb@google.com/
[9] https://lore.kernel.org/all/20231028003819.652322-1-surenb@google.com/
Andrea Arcangeli (2):
mm/rmap: support move to different root anon_vma in
folio_move_anon_rmap()
userfaultfd: UFFDIO_MOVE uABI
Suren Baghdasaryan (3):
selftests/mm: call uffd_test_ctx_clear at the end of the test
selftests/mm: add uffd_test_case_ops to allow test case-specific
operations
selftests/mm: add UFFDIO_MOVE ioctl test
Documentation/admin-guide/mm/userfaultfd.rst | 3 +
fs/userfaultfd.c | 72 +++
include/linux/rmap.h | 5 +
include/linux/userfaultfd_k.h | 11 +
include/uapi/linux/userfaultfd.h | 29 +-
mm/huge_memory.c | 122 ++++
mm/khugepaged.c | 3 +
mm/rmap.c | 30 +
mm/userfaultfd.c | 599 +++++++++++++++++++
tools/testing/selftests/mm/uffd-common.c | 39 +-
tools/testing/selftests/mm/uffd-common.h | 9 +
tools/testing/selftests/mm/uffd-stress.c | 5 +-
tools/testing/selftests/mm/uffd-unit-tests.c | 192 ++++++
13 files changed, 1115 insertions(+), 4 deletions(-)
--
2.43.0.rc1.413.gea7ed67945-goog
Doing a ksft_print_msg() before the ksft_print_header() seems to confuse
the ksft framework in a strange way: running the test on the cmdline
results in the expected output.
But piping the output somewhere else, results in some odd output,
whereby we repeatedly get the same info printed:
# [INFO] detected THP size: 2048 KiB
# [INFO] detected hugetlb page size: 2048 KiB
# [INFO] detected hugetlb page size: 1048576 KiB
# [INFO] huge zeropage is enabled
TAP version 13
1..190
# [INFO] Anonymous memory tests in private mappings
# [RUN] Basic COW after fork() ... with base page
# [INFO] detected THP size: 2048 KiB
# [INFO] detected hugetlb page size: 2048 KiB
# [INFO] detected hugetlb page size: 1048576 KiB
# [INFO] huge zeropage is enabled
TAP version 13
1..190
# [INFO] Anonymous memory tests in private mappings
# [RUN] Basic COW after fork() ... with base page
ok 1 No leak from parent into child
# [RUN] Basic COW after fork() ... with swapped out base page
# [INFO] detected THP size: 2048 KiB
# [INFO] detected hugetlb page size: 2048 KiB
# [INFO] detected hugetlb page size: 1048576 KiB
# [INFO] huge zeropage is enabled
Doing the ksft_print_header() first seems to resolve that and gives us
the output we expect:
TAP version 13
# [INFO] detected THP size: 2048 KiB
# [INFO] detected hugetlb page size: 2048 KiB
# [INFO] detected hugetlb page size: 1048576 KiB
# [INFO] huge zeropage is enabled
1..190
# [INFO] Anonymous memory tests in private mappings
# [RUN] Basic COW after fork() ... with base page
ok 1 No leak from parent into child
# [RUN] Basic COW after fork() ... with swapped out base page
ok 2 No leak from parent into child
# [RUN] Basic COW after fork() ... with THP
ok 3 No leak from parent into child
# [RUN] Basic COW after fork() ... with swapped-out THP
ok 4 No leak from parent into child
# [RUN] Basic COW after fork() ... with PTE-mapped THP
ok 5 No leak from parent into child
Reported-by: Nico Pache <npache(a)redhat.com>
Fixes: f4b5fd6946e2 ("selftests/vm: anon_cow: THP tests")
Signed-off-by: David Hildenbrand <david(a)redhat.com>
---
tools/testing/selftests/mm/cow.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/mm/cow.c b/tools/testing/selftests/mm/cow.c
index 7324ce5363c0c..6f2f839904416 100644
--- a/tools/testing/selftests/mm/cow.c
+++ b/tools/testing/selftests/mm/cow.c
@@ -1680,6 +1680,8 @@ int main(int argc, char **argv)
{
int err;
+ ksft_print_header();
+
pagesize = getpagesize();
thpsize = read_pmd_pagesize();
if (thpsize)
@@ -1689,7 +1691,6 @@ int main(int argc, char **argv)
ARRAY_SIZE(hugetlbsizes));
detect_huge_zeropage();
- ksft_print_header();
ksft_set_plan(ARRAY_SIZE(anon_test_cases) * tests_per_anon_test_case() +
ARRAY_SIZE(anon_thp_test_cases) * tests_per_anon_thp_test_case() +
ARRAY_SIZE(non_anon_test_cases) * tests_per_non_anon_test_case());
--
2.41.0
Add parsing of attributes as diagnostic data. Fixes issue with test plan
being parsed incorrectly as diagnostic data when located after
suite-level attributes.
Note that if there does not exist a test plan line, the diagnostic lines
between the suite header and the first result will be saved in the suite
log rather than the first test case log.
Signed-off-by: Rae Moar <rmoar(a)google.com>
---
Note this patch is a resend but I removed the second patch in the series
so now it is a standalone patch.
tools/testing/kunit/kunit_parser.py | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/tools/testing/kunit/kunit_parser.py b/tools/testing/kunit/kunit_parser.py
index 79d8832c862a..ce34be15c929 100644
--- a/tools/testing/kunit/kunit_parser.py
+++ b/tools/testing/kunit/kunit_parser.py
@@ -450,7 +450,7 @@ def parse_diagnostic(lines: LineStream) -> List[str]:
Log of diagnostic lines
"""
log = [] # type: List[str]
- non_diagnostic_lines = [TEST_RESULT, TEST_HEADER, KTAP_START, TAP_START]
+ non_diagnostic_lines = [TEST_RESULT, TEST_HEADER, KTAP_START, TAP_START, TEST_PLAN]
while lines and not any(re.match(lines.peek())
for re in non_diagnostic_lines):
log.append(lines.pop())
@@ -726,6 +726,7 @@ def parse_test(lines: LineStream, expected_num: int, log: List[str], is_subtest:
# test plan
test.name = "main"
ktap_line = parse_ktap_header(lines, test)
+ test.log.extend(parse_diagnostic(lines))
parse_test_plan(lines, test)
parent_test = True
else:
@@ -737,6 +738,7 @@ def parse_test(lines: LineStream, expected_num: int, log: List[str], is_subtest:
if parent_test:
# If KTAP version line and/or subtest header is found, attempt
# to parse test plan and print test header
+ test.log.extend(parse_diagnostic(lines))
parse_test_plan(lines, test)
print_test_header(test)
expected_count = test.expected_count
base-commit: b85ea95d086471afb4ad062012a4d73cd328fa86
--
2.43.0.rc2.451.g8631bc7472-goog
Hi,
> >
> > Please, extend libnetfilter_conntrack to support for this feature,
> > there is a filter API that can be used for this purpose.
>
> I will do that and post it here (or in the next version) once i am done.
>
A patch for this is now on netfilter-devel at [1].
[1]: https://marc.info/?l=netfilter-devel&m=170176886315385&w=2
Thanks
Hello,
kernel test robot noticed "kernel-selftests.seccomp.seccomp_bpf.fail" on:
commit: 95084d9b2b5f0b593724819288f3cb4e2c585cb0 ("[PATCH v3 3/3] selftests/seccomp: Test seccomp filter load and attach")
url: https://github.com/intel-lab-lkp/linux/commits/Hengqi-Chen/seccomp-Introduc…
base: https://git.kernel.org/cgit/linux/kernel/git/kees/linux.git for-next/seccomp
patch link: https://lore.kernel.org/all/20231129053440.41522-4-hengqi.chen@gmail.com/
patch subject: [PATCH v3 3/3] selftests/seccomp: Test seccomp filter load and attach
in testcase: kernel-selftests
version: kernel-selftests-x86_64-60acb023-1_20230329
with following parameters:
group: group-s
compiler: gcc-12
test machine: 36 threads 1 sockets Intel(R) Core(TM) i9-10980XE CPU @ 3.00GHz (Cascade Lake) with 32G memory
(please refer to attached dmesg/kmsg for entire log/backtrace)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <oliver.sang(a)intel.com>
| Closes: https://lore.kernel.org/oe-lkp/202312051652.ecd5fbc7-oliver.sang@intel.com
we noticed one test added in this commit can pass, but another will fail.
# # RUN global.seccomp_filter_load_and_attach ...
# # OK global.seccomp_filter_load_and_attach
# ok 56 global.seccomp_filter_load_and_attach
# # RUN global.seccomp_attach_fd_failed ...
# # seccomp_bpf.c:4792:seccomp_attach_fd_failed:Expected errno (22) == EFAULT (14)
# # seccomp_attach_fd_failed: Test terminated by assertion
# # FAIL global.seccomp_attach_fd_failed
# not ok 57 global.seccomp_attach_fd_failed
...
# # FAILED: 97 / 98 tests passed.
# # Totals: pass:97 fail:1 xfail:0 xpass:0 skip:0 error:0
not ok 1 selftests: seccomp: seccomp_bpf # exit=1
we applied the patch set upon 31c65705a8cfa like below:
95084d9b2b5f0 (linux-review/Hengqi-Chen/seccomp-Introduce-SECCOMP_LOAD_FILTER-operation/20231129-134337) selftests/seccomp: Test seccomp filter load and attach
8fcda1c36e519 seccomp: Introduce new flag SECCOMP_FILTER_FLAG_FILTER_FD
bd86f21cfe1e0 seccomp: Introduce SECCOMP_LOAD_FILTER operation
31c65705a8cfa (kees/for-next/seccomp, kees/for-linus/seccomp) perf/benchmark: fix seccomp_unotify benchmark for 32-bit
ce9ecca0238b1 (tag: v6.6-rc2, hyperv/hyperv-next) Linux 6.6-rc2
not sure if this is the correct base, or is there any other dependency to run
new test seccomp_attach_fd_failed?
The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20231205/202312051652.ecd5fbc7-oliv…
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Fix an out of bounds access reported in
https://lore.kernel.org/oe-lkp/202311201431.57aae8f3-oliver.sang@intel.com
Make sure that the ctl_table header size is greater than 0 before
evaluating if a ctl_table is permanently empty; this evaluation accesses
the first element regardless of the size. Adjusted the ctl_table_size of
Permanently empty ctl_table registers to 1 as they the check now
requires them to have size greater than 0. Added tests for empty
directory handling; in response to the path followed by empty ctl_tables
changing slightly. Clarified the results of sysctl self tests to more
easily identify which ones are OK, Skipped and Failed.
Comments are greatly appreciated
Best
Signed-off-by: Joel Granados <j.granados(a)samsung.com>
---
Joel Granados (3):
sysctl: Fix out of bounds access for empty sysctl registers
sysctl: Add a selftest for handling empty dirs
sysclt: Clarify the results of selftest run
fs/proc/proc_sysctl.c | 9 +-
lib/test_sysctl.c | 29 ++++++
tools/testing/selftests/sysctl/sysctl.sh | 146 ++++++++++++++++++-------------
3 files changed, 121 insertions(+), 63 deletions(-)
---
base-commit: 8b793bcda61f6c3ed4f5b2ded7530ef6749580cb
change-id: 20231121-jag-fix_out_of_bounds_insert-86380d1bc95e
Best regards,
--
Joel Granados <j.granados(a)samsung.com>
This patchset adds two kfunc helpers, bpf_xdp_get_xfrm_state() and
bpf_xdp_xfrm_state_release() that wrap xfrm_state_lookup() and
xfrm_state_put(). The intent is to support software RSS (via XDP) for
the ongoing/upcoming ipsec pcpu work [0]. Recent experiments performed
on (hopefully) reproducible AWS testbeds indicate that single tunnel
pcpu ipsec can reach line rate on 100G ENA nics.
Note this patchset only tests/shows generic xfrm_state access. The
"secret sauce" (if you can really even call it that) involves accessing
a soon-to-be-upstreamed pcpu_num field in xfrm_state. Early example is
available here [1].
[0]: https://datatracker.ietf.org/doc/draft-ietf-ipsecme-multi-sa-performance/03/
[1]: https://github.com/danobi/xdp-tools/blob/e89a1c617aba3b50d990f779357d6ce286…
Changes from v3:
* Place all xfrm bpf integrations in xfrm_bpf.c
* Avoid using nval as a temporary
* Rebase to bpf-next
* Remove extraneous __failure_unpriv annotation for verifier tests
Changes from v2:
* Fix/simplify BPF_CORE_WRITE_BITFIELD() algorithm
* Added verifier tests for bitfield writes
* Fix state leakage across test_tunnel subtests
Changes from v1:
* Move xfrm tunnel tests to test_progs
* Fix writing to opts->error when opts is invalid
* Use __bpf_kfunc_start_defs()
* Remove unused vxlanhdr definition
* Add and use BPF_CORE_WRITE_BITFIELD() macro
* Make series bisect clean
Changes from RFCv2:
* Rebased to ipsec-next
* Fix netns leak
Changes from RFCv1:
* Add Antony's commit tags
* Add KF_ACQUIRE and KF_RELEASE semantics
Daniel Xu (10):
xfrm: bpf: Move xfrm_interface_bpf.c to xfrm_bpf.c
bpf: xfrm: Add bpf_xdp_get_xfrm_state() kfunc
bpf: xfrm: Add bpf_xdp_xfrm_state_release() kfunc
libbpf: Add BPF_CORE_WRITE_BITFIELD() macro
bpf: selftests: test_loader: Support __btf_path() annotation
libbpf: selftests: Add verifier tests for CO-RE bitfield writes
bpf: selftests: test_tunnel: Setup fresh topology for each subtest
bpf: selftests: test_tunnel: Use vmlinux.h declarations
bpf: selftests: Move xfrm tunnel test to test_progs
bpf: xfrm: Add selftest for bpf_xdp_get_xfrm_state()
include/net/xfrm.h | 9 +
net/xfrm/Makefile | 7 +-
net/xfrm/xfrm_bpf.c | 232 ++++++++++++++++++
net/xfrm/xfrm_interface_bpf.c | 110 ---------
net/xfrm/xfrm_policy.c | 2 +
tools/lib/bpf/bpf_core_read.h | 32 +++
.../selftests/bpf/prog_tests/test_tunnel.c | 162 +++++++++++-
.../selftests/bpf/prog_tests/verifier.c | 2 +
tools/testing/selftests/bpf/progs/bpf_misc.h | 1 +
.../selftests/bpf/progs/bpf_tracing_net.h | 1 +
.../selftests/bpf/progs/test_tunnel_kern.c | 138 ++++++-----
.../bpf/progs/verifier_bitfield_write.c | 100 ++++++++
tools/testing/selftests/bpf/test_loader.c | 7 +
tools/testing/selftests/bpf/test_tunnel.sh | 92 -------
14 files changed, 624 insertions(+), 271 deletions(-)
create mode 100644 net/xfrm/xfrm_bpf.c
delete mode 100644 net/xfrm/xfrm_interface_bpf.c
create mode 100644 tools/testing/selftests/bpf/progs/verifier_bitfield_write.c
--
2.42.1